Dual interface smart cards incorporate an IC module which provides both direct contact and contactless interfaces (hereinafter “dual interface integrated circuit module”). Various arrangements of dual interface IC module and dual interface smart card, and methods of fabrication thereof are known.
FIG. 1A illustrates an existing smart card 100 incorporating an IC module 10 which requires a double plated module tape. A bonding side 11 of the IC module 10 is plated with conductive contact pads 12a for connecting with extracted terminals or portions 13 of an antenna embedded in the card body 14. A contact side or IC connector 15 of the IC module 10 is plated with conductive contact pads 12b (see FIG. 1B). By plating both sides of the module tape, the IC module is provided with a set of contact pads 12b on its contact side, which allow contact-based signal transmission with a contact-based card reader, and a another set of contact pads 12a on its bonding side which serve as points of contact between the IC module and an antenna embedded in the card body, wherein the antenna allows contact-free signal transmission to a contactless card reader.
To address the issues associated with double side plated tape construction, U.S. Pat. No. 9,390,365 B2 (Integrated circuit module for a dual-interface smart card) discloses a dual-interface IC module which utilizes a single-side plated module tape construction. Particularly, unused contact pads C4 and C8 are utilized as antenna contact pads for a dual-interface smart card. Based on current industry standards for smart cards, International Organization for Standardization (ISO) 7816, contact pads C4 and C8 are commonly designated as being reserved for future use (RFU), and are not typically required to deliver a particular signal to IC module. Remaining ISO designated contact pads C1 to C3, C5 and C7 are typically designated to deliver signals to IC module.
US Patent Application Publication No. 2017/0270398 A1 (Method for producing a circuit for a chip card module and circuit for a chip card module) discloses another single-side plated flexible electrical circuit for implementing a method for producing a chip card module.